Perhaps you should try some spelling variations:
nhieu viec » hieu viec, nhien viet
sach nuoc » sach duoc, cac nuoc, bach tuoc
hieu van » hieu va, thien van, lieu va
doi cua » dai cua, hoi cua
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
sac ky » cac ky, sai ky
su sac » su sach, su cac, su xac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky nang xa hoi. ((nhieu viec) or (hieu van)) sach nuoc ((va danh) OR (va dinh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang xa hoi. ((nhieu viec) OR (hieu van)) sach nuoc ((va danh) OR (va dinh)) doi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang xa hoi. ((nhieu viec) or (hieu van)) sach nuoc ((va danh) OR (va dinh)) doi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang xa hoi. ((nhieu viec) or (hieu van)) sach nuoc ((va danh) OR (va dinh)) doi cua tre*.